ISCHEMIA trial: How to apply the results to clinical practice

Abstract

During the last years two questions have been continuously asked in chronic coronary syndromes: (1) Do revascularization procedures (coronary artery bypass grafting or percutaneous coronary intervention) really improve symptoms of angina? and (2) Do these techniques improve outcomes, i.e. do they prevent new myocardial infarction events and cardiovascular death? Therefore, there was a need for a large definitive trial. This study was the ISCHEMIA trial, a large, multicentric trial sponsored by the National Heart, Lung, and Blood Institute. The main trial compared coronary revascularization and optimal medical treatment (OMT) vs OMT alone in 5179 patients enrolled after a stress test. During a median 3.2-year follow-up, 318 primary outcome events occurred; the adjusted hazard ratio for the invasive strategy as compared with the conservative strategy was 0.93 (95% confidence interval 0.80-1.08, P = 0.34). The ISCHEMIA trial deeply disrupted many of our prior attitudes regarding management strategies for patients with stable coronary artery disease. The findings underscore the benefits of disease-modifying OMT for stable coronary artery disease patients. The main purposes of ischemia assessment before this trial were: Diagnostic purposes, assessment of outcome, and adding to decision-making processes. Obviously, this changed after the trial results. The results of ISCHEMIA might challenge the current diagnostic approach for stable angina patients recommended in the last European Society of Cardiology guidelines on chronic coronary disease that were based on studies published before the ISCHEMIA trial. In this editorial we propose our approach based on the ISCHEMIA study and the pretest probability for a positive test in patients with chronic coronary syndromes.

Keywords: Chronic coronary syndrome; Diagnosis; ISCHEMIA; Stable angina; Stress testing; Therapy.

Figure 1

Algorithm for chronic coronary syndrome with high pretest probability of positive test for ischemia. ¹Previously known as stable angina. ²Stress echocardiography (non-contrast technique), single photon emission computed tomography (non-contrast technique), or magnetic resonance imaging (contrast technique). CAD: Coronary artery disease; CCTA: Coronary computed tomography angiography; GFR: Estimated Glomerular filtration rate (mL/min/1.73 m²); LMD: Left main disease; OMT: Optimal medical therapy.

Figure 2

Algorithm for chronic coronary syndrome with low to moderate pretest probability of positive test for ischemia. ¹Previously known as stable angina. ²Stress echocardiography [any glomerular filtration rate (GFR) (mL/min/1.73 m²)], single photon emission computed tomography (any GFR), or magnetic resonance imaging (only if GFR > 30). CCTA: Coronary computed tomography angiography; LMD: Left main disease; OMT: Optimal medical therapy.